A need has always existed for a method of establishing the age and authenticity of documents, particularly for legal and business purposes. For documents written on paper, methods currently exist for establishing the age of a document by analysis of the chemical composition of the paper and the ink. Further, handwriting analysis can be used to establish the authenticity of the document signatures. These methods, however, are not practical for widespread use and require a significant level of expertise to establish either the age or the authenticity of the document signatures.
Impartial third party notaries have been typically relied upon to establish both the age and authenticity of paper documents. With such an approach, there is no assurance against collusion or conspiracies to defraud involving a third party notary. Still, further, where a large volume of transactions or documents related thereto, such as with financial transactions, is involved, the task of third party notarization becomes too cumbersome and the ability to immediately notarize the document is not possible.
With the rapid qrowth of electronic documents and the movement toward a paperless society, there is an increasing need for establishing not only the integrity of an electronic document but the exact date and time, and, possibly, even the place at which a document was created or last modified.
Prior time stamp apparatus have used internal clock modules contained within a data processing system or the time stamp apparatus itself to generate the value of the day and time within a time stamp. For security purposes, this solution is unacceptable since such internal clocks are readily modifiable by the user to reset the date and time upon computer initialization or power loss. One such apparatus is disclosed in U.S. Pat. No. 5,136,643, issued to Fisher, entitled PUBLIC/KEY DATE TIME NOTARY FACILITY. The system disclosed in Fisher contains one or more digital clocks, the values of which are averaged and used as part of a notary time stamp value. Although the clock module in the Fisher apparatus has been designed to prevent physical tampering, the problem of continuous power to the clock is not solved, since even backup batteries lose power eventually. Further, since the internally generated clock signal is not a universally recognized, the authenticity of the time stamp is not universally recognized. United States Patent 5,189,700, issued to Blandford, entitled DEVICES TO SUPPLY AUTHENTICATED TIME AND TIME STAMP AND AUTHENTICATE DIGITAL DOCUMENTS, likewise discloses a device in which a resident real time clock provides the source of time for the time stamps. The apparatus disclosed in Blandford suffers from the same inherent problems as the Fisher patent, namely, the internally generated clock is not a universally recognized value for the time at any given instance. Hence, the credibility of the time stamps issued therefrom is similarly not universally recognized.
Accordingly, in light of the above deficiencies in previously attempted solutions, a need exists for a method and apparatus by which a highly accurate and universally accepted notary stamp may be applied to both paper and electronic documents and associated transactions, such a stamp being useful to both compute the age of a document, and, in the case of electronic documents, verify the authenticity and integrity of the document. A further need exists for a method of providing a "virtual seal" on computer files and records so that the exact date, time and place of the sealing may be later ascertained. Further, a need exists to determine whether modifications or subsequent edits to such sealed documents has occurred and, possibly, even a history of such modifications to the documents.